Navegando en un punto de sonda en la carta de 5 metros (San Ciprián) y obteniendo del anuario de mareas las siguientes lecturas: Hora de la pleamar=08:30, altura de la pleamar=5,55m; Hora de la bajamar=14:45, altura de la bajamar 2,05m. ¿Cuál de las siguientes respuestas más se aproxima a la sonda en el momento a las 11:25?Sailing at a point with a charted sounding of 5 metres (San Ciprián) and reading from the tide tables: High water time = 08:30, height 5.55 m; Low water time = 14:45, height 2.05 m. Which answer is closest to the sounding at 11:25?

Correct answer: d) 8.98 metres.

Why it is correct

D = 6h 15m and t = 2h 55m. h = 3.80 + 1.75 × cos(84º) = 3.98 m. Sounding: 5 + 3.98 = 8.98 m.

Why the others are not

• a) It does not match the working.
• b) It does not match the working.
• c) It does not match the working.

How to work it out in the exam

1. Find t, the time since the first tide, and D, the duration between them.
2. h = mean + (first − second) / 2 × cos(180º × t / D).
3. Sounding = charted sounding + h.

Where this question comes from

• Ministerio de Transportes (Madrid) · 2022 · Convocatoria de diciembre · PY Test 1 · question 31 Official paper · Official answer key
• Ministerio de Transportes (Madrid) · 2022 · Convocatoria de diciembre · PY Test 2 · question 35 Official paper · Official answer key

Try it: Tide trainer

Pending instructor review. Machine translation, not reviewed.